Firstly you did not mention the last time you changed the engine oil. I suggest that since your beat has done 30000 kms, you better change the engine oil. If your service record is as per schedule of free services and paid ones, you're being mocked and the whopping 13000 Rs is not essential . Apart from these, based on your usage the parts may have worn down.Take your car to a known workshop and have their opinion before proceeding further.